Means for interlocking folders



March 7, 1950 ITFIE 2,499,436

MEANS F01? INTERLOCKING FOLDERS Filed Oct. 8, 1945 INVENTOR FRED A.WHITFIELD ATTORNEYS I BY :Fig' E.

Patented Mar. 7, 1950 MEANS FOR INTERLOC KIN G FOLDERS Fred A.Whitfield, Seattle, Wash; Alice L. Kaehler administratrix of said Fred.A. Whitfield,

deceased Application October 8, 1945, Serial No. 620,872

1 Claim. (01. 281-29) My present invention'relates to method and meansfor interlocking folders and, more particularly, to a system of formingand interlocking opposed tabs in two adjacent pieces of sheet materialwhich are to be joined together along common juxtaposed edges.

With particular reference to articles commonly used in direct mailadvertising, but having in mind many other uses obvious to those skilledin the art of locking means for folders and the like, I have found thatthere is a great need for a suitable closure. Those that I have observedin use usually required a crimped staple, a gummed sticker or stamp, ora notched tab integral with one of the leaves to flt into a slit-in theother leaf. In the latter instance, it is often found that there is agreat waste of paper stock or sheet material due to the fact that thetab has to be cut to extend beyond the edge with which it is integral,in order that it may extend into the slit of the opposed sheet. The maindifficulty of such an arrangement arises where the exposed faces of thesheets are printed. Either a portion of that printing is then covered bythe tab or the tab must be printed with the same copy appearingthereunder. This requires critical register during printing. Withrespect to the stapling or sticker fastenings, additional material isnecessitated and often mechanism is required for the application of thefastener, both of which conditions are somewhat undesirable.

Having in mind the defects of the prior art, it is an object of myinvention to provide a closure for folders, and the like, that iscapable of construction by a printer using his already available cuttingmeans and without requiring elaborate mechanisms for volume production.

Another object of my invention is to provide, in a closure of the typedescribed, opposed elements capable of securely locking together twojuxtaposed sheets of a folder or the like, and which can be brought intothe closed position with facility, but which will not be unlocked uponmere relative movement without distortion of the locked sheet.

A still further and more specific object of my invention is theprovision, in a closure of the type described, of an arrangement ofparts which will join two sheets without requiring additional fasteningmeans.

The foregoing objects, and others ancillary thereto, I prefer toaccomplish as follows:

According to a preferred embodiment of my intion, I form suitableopposed locking slits in two adjacent edges, whereby the same may beinterlocked. Specifically, the locking means comprises a slit in eachedge extending inwardly in a direction other than at right angles for apredetermined distance. The slits usually will be formed so that whenthe two sheets are brought into side-by-side position, the innerterminals of the slits will coincide, and the tabs formed thereby willbe capable of being overlapped and interlocked. In a preferred form ofmy invention, the slits are curved, but in an alternative form, they maylie in a straight line. Such being the case, when the two pages orsheets having slits therein are brought together and the slitsinterlocked, there will beobtained a 'suitable-closure of such a naturethat-the pages-can'- not be opened and the interior exposed without anintentional unlocking of the interlocked closure tabs. By arranging in asingle edge on each of two sheets, opposed tabs, the sheets may belocked together against relative movement.

The novel features that I consider characteristic of my invention, areset forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional objects and advantages thereof willbest be understood from the following description of a specificembodiment when read in connection with the accompanying drawings, inwhich:

vention, in a folder or leaflet of booklike construc- Fig. 1 is aperspective view of an unlocked leaflet embodying my locking means:

Fig. 2 is a perspective view of a leaflet showing it in the lockingposition;

Fig. 3 is a perspective view of a fragmentary portion of a sheet showinga modified form of the interlocking elements;

Fig. 4 is an edge view of an element disclosing the method ofinterlocking opposed locking elements between two sheets; and

Fig. 5 is an edge view of a leaflet in the locked position.

A closure for folders to overcome the defects hereinbefore enumeratedmust have at least two totally distinct characteristics; it must becapable of being simply and quickly formed and locked, and it must alsoprovide a closure lock arrangement which will endure a reasonable amountof handling and hard usage, especially in the mails.

Accordingly, a preferred embodiment of my invention, referring toFigures 1 and 2 of the drawing, is constituted by a folder, in the edgesof which have been formed interlocking tabs. For the purposes of thisdescription, the folder comright angle to that edge, and in thisinstance, is

shown as being curved. Thus is formed the tab I9. In the back cover 12,in edge I3, is also formed the slit 29, to produce tab 2t. Slits 118 and20 extend inwardly in converging directions. When the two sheets in andH are brought side by side, as they appear in Fig. 1., it will beobserved that the tabs 19 and 21 are oppositely directed, and that thepointed end of the tab 19,

as well as the pointed "end of the tab 2i, lie adjacent the root of theopposite tab. In. other words, the tabs overlap each other, and thispermits-them to be interlocked in-the manner shown in Figures 4 and: 5.,which is accomplished by so distorting the tab that the outer faces oftabs I 9 and 2| are placed contiguous to each. other and. the inner.ends of. the slits i9 and 2b are caused to coincide in the manner shownin Fig 2. The foregoing described arrangement is suitable under certaincircumstances to form a closure for folders. In certain cases, however,it has been found desirable to insurev unlocking. of. the interlockedcover faces of the folder to provide auxiliary tabs'23 and 24,-each ofwhich is directed oppositely to the corresponding, tab of the same coverpage in which each is formed. In other wordsthe tabs [9. and 23 aredirected toward the topand'bottom edges of the page [hand away from eachother, while the. tabs 2! and. .24 are likewise directed toward the topand bottom of the page 1-2., but toward each other. Thus, when the tabsl9 and 21 are locked together, and the tabs 23 and 24 are lockedtogether, the folder is closed in a manner more accurately shown .inFig. 2, as well as in Fig. 5-

In. a slightly modified form of. the invention, the sheet 30, having theedge 31,, is slit at 3.2, to form. the tab 33. The principal diiierencebetween the arrangement inFig. 3 and that ofFig.

1 is that the slit 32 lies in a straight line, rather than in a curved.line. The function of pointed tabs 33, as distinguished from tab i9, isno different in serving as. a closure element.

While I have shown and described particular embodiments of my invention,it will occur to those skilled in the art that various changes andmodifications may be made without departing from the invention, and Itherefore aim in the appended claim to cover all such changes andmodifications as fall within the true spirit and scope of my invention-Having thus described my invention, I claim:

In a booklet of the type having a front cover member; a plurality ofpages disposed behind saidiront cover member and having a width lessthan that of the front cover member; a rear cover member identical insize with that of the front.- cover member; means for joining said frontcover member, the interposed pages, and the rear cover member along onemargin to form a booklet, said cover members and pa es being arranged sothat the free edges of the front and rear cover members protrude pastthe free edges of the interposed pages; locking means for the said freeedges. of said cover members, comprising: formed in the protruding edgeof each of said cover members, an arcuate slit extending inward-from.said edge, the slit of one said sheet being in a direction to intersecton its inner end the. slit ,of the other cover member when said sheets.are juxtaposed, said slits being of like length; a second reversed pairof slits in said cover members spaced from said first pair of edgeslits, said second pair of slits being of like nature with said firstpair of slits, the s its in one cover member being directed toward eachother, and the slits in the opposite cover being directed away from eachother.

FREDA. WHITFIELD.

REFERENCES. CITED The iollowingre'ferences are of record in the file ofpatent:

UNITED STATES PATENTS Number Name Date 2,218,360 Rokol Oct. 15, 19402,285,234 Tauber s June .2, 1942 2 ,325,999 Snyder Aug. 3, 19432,455,795 Murphy Dec. I, 1948 FOREIGN PATENTS Number Country Date 49,286Germany Oct. 1889

